1. Technical Field
This disclosure relates generally to imaging systems, and more particularly, to optical imaging systems using baffles.
2. Related Art
Optical instruments are typically used to generate images of objects and may include cameras or telescopes. Both cameras and telescopes may be used for general everyday use or may be used in space vehicles (for example, satellites, space shuttles, nano-satellites, international space station and others).
Optical instruments typically use imaging systems (also referred to as optical systems) to generate images. However, sometimes these images may have flare. Flare is the collective name for colored spots, ghost images or veils that impair or distort an image. Flare is typically caused by stray light from a source of light (for example, the sun) impinging on a frontal lens of an imaging system. Typically, stray light is propagated between lens elements before finally reaching an imaging film or a digital sensor.
Controlling flare is desirable especially in imaging systems for space vehicle optical instruments because space vehicle optical instruments are exposed to extreme and intense illumination due to the absence of atmosphere in space. To form a clear and sharp image, it is desirable to block stray light rays from reaching a lens (or glass elements) of the imaging systems. Typically, imaging systems use sunshields (shades or hoods) for shielding a lens from stray light. The sunshields protrude from the imaging system. In addition, imaging systems may use a plurality of baffles (or vanes, used interchangeably) outside the optical path. Typically, baffles are placed perpendicular to the optical path of an imaging system for blocking the propagation of stray light.
However, in conventional systems, baffles placed perpendicular to the optical path, and sunshields fail to effectively block stray light because stray light may still propagate and clutter (or degrade) a final image.
Therefore there is a need for an optical imaging system for use in optical instruments that reduces flare and produces sharp and clear images.